Paging receivers sometimes include the capability to scan across a predetermined frequency spectrum to locate a channel carrying desired paging data. The scanning operation, however, is energy intensive and reduces the battery life available for the more productive task of receiving pages.
The power consumed by the scanning process is directly related to the number of channels examined. A method has been devised to reduce the number of channels that are examined and thereby increase the battery life. This method involves transmitting with each paging signal a list of paging channels that are in use in the area surrounding the transmitting station. On finding one station, the receiver is thus provided a small local list of other stations that it can examine for data if the original station is lost, obviating the need to scan the entire frequency spectrum.
The above technique works well. However, in certain situations it is impractical for each transmitter to send a unique list of surrounding stations. This is the case when a plurality of geographically diverse stations are provided the same paging data though a network of relay stations.
If only one list is transmitted in such a wide-area network, the receiver may attempt to scan channels that are not in use in the current location. In this event, the list is a detriment to finding paging signals, not an aid. The alternative is to include a comprehensive list that includes all the paging channels throughout the network. However, such a list is likely to be so long as to provide no benefit in locating a suitable paging channel.
It is an object of the present invention to provide local channel lists to paging receivers served by networked paging transmitters.
It is another object of the present invention to broadcast a plurality of local channel lists and to permit individual paging receivers to identify the list pertinent to their particular geographical area.